<!DOCTYPE HTML>
<html lang="zh" class="light" dir="ltr">
    <head>
        <!-- Book generated using mdBook -->
        <meta charset="UTF-8">
        <title>校验和生成工具 - panda note :)</title>


        <!-- Custom HTML head -->
        
        <meta name="description" content="The note book of pandazhangs">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <meta name="theme-color" content="#ffffff">

        <link rel="icon" href="../favicon.svg">
        <link rel="shortcut icon" href="../favicon.png">
        <link rel="stylesheet" href="../css/variables.css">
        <link rel="stylesheet" href="../css/general.css">
        <link rel="stylesheet" href="../css/chrome.css">
        <link rel="stylesheet" href="../css/print.css" media="print">

        <!-- Fonts -->
        <link rel="stylesheet" href="../FontAwesome/css/font-awesome.css">
        <link rel="stylesheet" href="../fonts/fonts.css">

        <!-- Highlight.js Stylesheets -->
        <link rel="stylesheet" href="../highlight.css">
        <link rel="stylesheet" href="../tomorrow-night.css">
        <link rel="stylesheet" href="../ayu-highlight.css">

        <!-- Custom theme stylesheets -->
        <link rel="stylesheet" href="../js/whichlang.css">

        <!-- MathJax -->
        <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
    </head>
    <body class="sidebar-visible no-js">
    <div id="body-container">
        <!-- Provide site root to javascript -->
        <script>
            var path_to_root = "../";
            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
        </script>

        <!-- Work around some values being stored in localStorage wrapped in quotes -->
        <script>
            try {
                var theme = localStorage.getItem('mdbook-theme');
                var sidebar = localStorage.getItem('mdbook-sidebar');

                if (theme.startsWith('"') && theme.endsWith('"')) {
                    localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
                }

                if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
                    localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
                }
            } catch (e) { }
        </script>

        <!-- Set the theme before any content is loaded, prevents flash -->
        <script>
            var theme;
            try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
            if (theme === null || theme === undefined) { theme = default_theme; }
            var html = document.querySelector('html');
            html.classList.remove('light')
            html.classList.add(theme);
            var body = document.querySelector('body');
            body.classList.remove('no-js')
            body.classList.add('js');
        </script>

        <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">

        <!-- Hide / unhide sidebar before it is displayed -->
        <script>
            var body = document.querySelector('body');
            var sidebar = null;
            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
            if (document.body.clientWidth >= 1080) {
                try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                sidebar = sidebar || 'visible';
            } else {
                sidebar = 'hidden';
            }
            sidebar_toggle.checked = sidebar === 'visible';
            body.classList.remove('sidebar-visible');
            body.classList.add("sidebar-" + sidebar);
        </script>

        <nav id="sidebar" class="sidebar" aria-label="Table of contents">
            <div class="sidebar-scrollbox">
                <ol class="chapter"><li class="chapter-item expanded "><a href="../chapter_1.html"><strong aria-hidden="true">1.</strong> 异步日志写设计实现</a></li><li class="chapter-item expanded "><a href="../chapter_2.html"><strong aria-hidden="true">2.</strong> 分布式一致性hash实现</a></li><li class="chapter-item expanded "><a href="../chapter_3.html"><strong aria-hidden="true">3.</strong> 文件多格式压缩实现</a></li><li class="chapter-item expanded "><a href="../snowflake.html"><strong aria-hidden="true">4.</strong> 雪花算法go 实现</a></li><li class="chapter-item expanded "><a href="../gopprof.html"><strong aria-hidden="true">5.</strong> 一个监控服务的pprof 优化流程</a></li><li class="chapter-item expanded "><a href="../subpush.html"><strong aria-hidden="true">6.</strong> 消息订阅推送实现</a></li><li class="chapter-item expanded "><a href="../tls_h2.html"><strong aria-hidden="true">7.</strong> tls 和 h2 使用简记</a></li><li class="chapter-item expanded "><a href="../grpc.html"><strong aria-hidden="true">8.</strong> gRPC 学习笔记</a></li><li class="chapter-item expanded "><a href="../etcd.html"><strong aria-hidden="true">9.</strong> etcd 学习笔记</a></li><li class="chapter-item expanded "><a href="../rust/rshsum.html" class="active"><strong aria-hidden="true">10.</strong> 校验和生成工具</a></li></ol>
            </div>
            <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                <div class="sidebar-resize-indicator"></div>
            </div>
        </nav>

        <!-- Track and set sidebar scroll position -->
        <script>
            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
            sidebarScrollbox.addEventListener('click', function(e) {
                if (e.target.tagName === 'A') {
                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
                }
            }, { passive: true });
            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
            sessionStorage.removeItem('sidebar-scroll');
            if (sidebarScrollTop) {
                // preserve sidebar scroll position when navigating via links within sidebar
                sidebarScrollbox.scrollTop = sidebarScrollTop;
            } else {
                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
                var activeSection = document.querySelector('#sidebar .active');
                if (activeSection) {
                    activeSection.scrollIntoView({ block: 'center' });
                }
            }
        </script>

        <div id="page-wrapper" class="page-wrapper">

            <div class="page">
                                <div id="menu-bar-hover-placeholder"></div>
                <div id="menu-bar" class="menu-bar sticky">
                    <div class="left-buttons">
                        <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
                            <i class="fa fa-bars"></i>
                        </label>
                        <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
                            <i class="fa fa-paint-brush"></i>
                        </button>
                        <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
                            <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
                        </ul>
                        <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
                            <i class="fa fa-search"></i>
                        </button>
                    </div>

                    <h1 class="menu-title">panda note :)</h1>

                    <div class="right-buttons">
                        <a href="../print.html" title="Print this book" aria-label="Print this book">
                            <i id="print-button" class="fa fa-print"></i>
                        </a>

                    </div>
                </div>

                <div id="search-wrapper" class="hidden">
                    <form id="searchbar-outer" class="searchbar-outer">
                        <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
                    </form>
                    <div id="searchresults-outer" class="searchresults-outer hidden">
                        <div id="searchresults-header" class="searchresults-header"></div>
                        <ul id="searchresults">
                        </ul>
                    </div>
                </div>

                <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
                <script>
                    document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
                    document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
                    Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
                        link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
                    });
                </script>

                <div id="content" class="content">
                    <main>
                        <h1 id="rhksum-生成校验和的cli-工具"><a class="header" href="#rhksum-生成校验和的cli-工具">rhksum 生成校验和的cli 工具</a></h1>
<hr />
<blockquote>
<p>标签： rust  md5  sha1  crc32</p>
<p><a href="https://gitee.com/adamszhang/rust-util/blob/master/rhksum">源码仓库连接</a></p>
</blockquote>
<h2 id="简单的功能设计和使用说明"><a class="header" href="#简单的功能设计和使用说明">简单的功能设计和使用说明</a></h2>
<p>首先rhksum 定位是能够容忍将校验和指定输出到文件，或者控制台上，所以对原先设想的base64 编解码做了舍弃；因为base64的长度是随输入内容变动的，所以如果指定一个大文件然后将编码的结构打印到控制台上，体验会非常糟糕，同时和其他三个生成编码的算法不相对称，base64 是可以从编码上恢复的，同时没有校验功能，所以没有嵌入这部分。</p>
<pre><code class="language-shell">rhksum -e crc32|md5|sha1 /
       -f  path/to/file  /
       -o  the out file  /
       -h help 
</code></pre>
<p>因为是一个命令行工具，所以一定是要能够支持管道符重定向输入的，所以在未指定文件时会自行推测从 stdin 开始获取。但是为了避免手动输入的滑稽场景，在检测到标准输入来源不是管道符就会退出，提前终止，避免需要手动触发退出；</p>
<h2 id="命令行解析"><a class="header" href="#命令行解析">命令行解析</a></h2>
<p>这部分用的是 clap 的 builder 模式，需要在使用 <code>cargo add clap --feature cargo</code> 来使部分功能生效；</p>
<pre><pre class="playground"><code class="language-rust"><span class="boring">#![allow(unused)]
</span><span class="boring">fn main() {
</span>// 配置命令行参数选项
  let matches = command!()
        .arg(
            arg!(-'e' --"encode" &lt;encode&gt; "set the encode format")
                .required(false) // 传入 false 可以使这个 参数变成可选的
                .value_parser(["crc32", "md5", "sha1"]),
        )
        .arg(
            arg!(-'f' --"file" &lt;file&gt;  "set the input file")
                .required(false)
                .value_parser(clap::builder::NonEmptyStringValueParser::new()),
        )
        .arg(arg!(-'o' --"output" &lt;output&gt; "set the out put file").required(false))
        .get_matches();

// 解析命令行参数
    // 先声明四个变量，分别应对标准io 和 文件io
    let mut ifile: File;
    let mut ofile: File;
    let mut stdin = stdin();
    let mut stdout = stdout();

    let f = matches.get_one::&lt;String&gt;("file");
    let o = matches.get_one::&lt;String&gt;("output");
    // 这个 e 是编码格式的选项
    let e = matches
        .get_one::&lt;String&gt;("encode")
        .expect("parser encode format failed");
    // 通过 io::Write  io::Read 这两个Traits 用来做动态类型，让各个mod 的方法在签名上统一
    let dest: &amp;mut dyn io::Write = match o {
        None =&gt; &amp;mut stdout,
        Some(ref a) =&gt; {
            ofile = File::create(a).expect("output file open failed");
            &amp;mut ofile
        }
    };
    let src: &amp;mut dyn io::Read = match f {
        None =&gt; {
            // 未指定输入文件的时候，主动检测标准输入是不是终端，是的话提前失败退出
            if stdin.is_terminal() {
                println!("dont support input by manual type");
                return;
            }
            &amp;mut stdin
        }
        Some(ref a) =&gt; {
            ifile = File::open(a).unwrap();
            &amp;mut ifile
        }
    };

<span class="boring">}</span></code></pre></pre>
<h2 id="模式匹配"><a class="header" href="#模式匹配">模式匹配</a></h2>
<pre><pre class="playground"><code class="language-rust"><span class="boring">#![allow(unused)]
</span><span class="boring">fn main() {
</span>    // 这部分要写的这么难看就是  
    // rust 会认为 &amp;std::string::String 和 &amp;str 不是一个类型，需要主动去转换；
    match &amp;e as &amp;str {
       
       "crc32" =&gt; crc32_::encode(&amp;mut *src, &amp;mut *dest),
        "md5" =&gt; md5::encode(&amp;mut *src, &amp;mut *dest),
        "sha1" =&gt; sha1::encode(&amp;mut *src, &amp;mut *dest),
        _ =&gt; {}    // 未匹配路径这里旧直接退出了，
        // 其实这个逻辑 分支会在命令行输入出被校验出来提前失败,所以这里不处理是可以的
    }
<span class="boring">}</span></code></pre></pre>
<h2 id="校验加密算法"><a class="header" href="#校验加密算法">校验加密算法</a></h2>
<p>这里三个mod 模块都是公开的，可以被作为库嵌入使用</p>
<pre><pre class="playground"><code class="language-rust"><span class="boring">#![allow(unused)]
</span><span class="boring">fn main() {
</span>pub mod crc32_ {
    use crc::{Crc, CRC_32_ISO_HDLC};
    use std::{io::Read, io::Write};
    pub fn encode(r: &amp;mut dyn Read, w: &amp;mut dyn Write) {
        let crc = Crc::&lt;u32&gt;::new(&amp;CRC_32_ISO_HDLC);
        let mut digest = crc.digest();
        let mut v = [0u8; 1024];
        loop {
            let cnt = r.read(&amp;mut v[..]).unwrap();
            if cnt == 0 {
                break;
            }
            digest.update(&amp;mut v[..cnt])
        }
        let checksum = format!("{0:&lt;8X}\n", digest.finalize()); // 大写的十六进制输出下32/4 最后有8位字符，通过0左填充以防长度问题
        // println!("result is {0:8}", checksum);
        let re = w.write(checksum.as_bytes());
        if re.is_err() {
            println!("err is {:#} ", re.expect_err("write error"))
        }
    }
}

pub mod md5 {
    use chksum_md5 as md5;
    use std::{io::Read, io::Write};
    pub fn encode(r: &amp;mut dyn Read, w: &amp;mut dyn Write) {
        let mut f = md5::reader::new(r);
        let mut buffer = Vec::new();
        f.read_to_end(&amp;mut buffer).unwrap();
        let digest = f.digest();
        let checksum = format!("{}\n", digest.to_string().to_uppercase());
        // println!("result is {}", checksum);
        let re = w.write(checksum.as_bytes());
        if re.is_err() {
            println!("err is {:#} ", re.expect_err("write error"))
        }
    }
}

pub mod sha1 {
    use sha1_smol::Sha1 as sha1;
    use std::{io::Read, io::Write};
    pub fn encode(r: &amp;mut dyn Read, w: &amp;mut dyn Write) {
        let mut digest = sha1::new();
        let mut v = [0u8; 1024];
        loop {
            let cnt = r.read(&amp;mut v[..]).unwrap();
            if cnt == 0 {
                break;
            }
            digest.update(&amp;mut v[..cnt])
        }
        let checksum = format!("{}\n", digest.digest().to_string().to_ascii_uppercase());
        // println!("result is {}", checksum);
        let re = w.write(checksum.as_bytes());
        if re.is_err() {
            println!("err is {:#} ", re.expect_err("write error"))
        }
    }
}


<span class="boring">}</span></code></pre></pre>
<p>这部分其实做的工作不多，但是这几个库的调用形式是有差异的，为了统一函数签名，还是花了些时间</p>

                    </main>

                    <nav class="nav-wrapper" aria-label="Page navigation">
                        <!-- Mobile navigation buttons -->
                            <a rel="prev" href="../etcd.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
                                <i class="fa fa-angle-left"></i>
                            </a>


                        <div style="clear: both"></div>
                    </nav>
                </div>
            </div>

            <nav class="nav-wide-wrapper" aria-label="Page navigation">
                    <a rel="prev" href="../etcd.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
                        <i class="fa fa-angle-left"></i>
                    </a>

            </nav>

        </div>

        <!-- Livereload script (if served using the cli tool) -->
        <script>
            const wsProtocol = location.protocol === 'https:' ? 'wss:' : 'ws:';
            const wsAddress = wsProtocol + "//" + location.host + "/" + "__livereload";
            const socket = new WebSocket(wsAddress);
            socket.onmessage = function (event) {
                if (event.data === "reload") {
                    socket.close();
                    location.reload();
                }
            };

            window.onbeforeunload = function() {
                socket.close();
            }
        </script>



        <script>
            window.playground_copyable = true;
        </script>


        <script src="../elasticlunr.min.js"></script>
        <script src="../mark.min.js"></script>
        <script src="../searcher.js"></script>

        <script src="../clipboard.min.js"></script>
        <script src="../highlight.js"></script>
        <script src="../book.js"></script>

        <!-- Custom JS scripts -->
        <script src="../js/fzf.umd.js"></script>
        <script src="../js/elasticlunr.js"></script>
        <script src="../js/import-html.js"></script>
        <script src="../js/whichlang.js"></script>


    </div>
    </body>
</html>
